hugolib: Improve menu generation for section pages with content
hugolib: Improve menu generation for section pages with content

When using the lazy blogger setting to automatically generate menu
entries from section pages, we now recognize section pages that have
content, and use the weight and linktitle configured in the frontmatter.

This way, we can use the lazy blogger automatic generation, and
influence menu order and translations, directly from the frontmatter.

Updates #2974

digitalcraftsman/hugo,anthonyfok/hugo,gohugoio/hugo,digitalcraftsman/hugo,gohugoio/hugo,gohugoio/hugo,mdhender/hugo,anthonyfok/hugo,mdhender/hugo,mdhender/hugo,mitchchn/hugo,fedelibre/hugo,fedelibre/hugo,fedelibre/hugo,fedelibre/hugo,mdhender/hugo,anthonyfok/hugo,mitchchn/hugo